Apparatus for extracting cores from the side wall of well bores



C. E. BURTv Sept. 3, 1935.

APPARATUS FOR EXTRACTING CORES FROM THE SIDE WALL OF WELL BORES Filed Sept. 12, 1954 IN V EN TOR. 6W 6. 75w. 7

A TTO S.

714 7A 5 IN r14 Patented Sept. 3, 1935 UNITED STATES.

APPARATUS FOR EXTRACTING CORES FROM THE SIDE WALL OF WELL BORES Clarence E. Burt, Los Angeles, Calif., assignor to Baker Oil Tools, Inc., Huntington Park, Calif., a corporation of California Application September 12, 1934, Serial No. 743,643

' 13 Claims.

This invention relates to the art of drilling oil wells and particularly pertains to an apparatus for extracting cores or samples from the side walls of well bores.

It is the principal object of the present invention to provide an efficient device for extracting cores or taking formation samples from the wall of an oil well bore at any desired depth in order that the character of the formation at any particular pointin the bore may be determined.

In carrying this object into practice, I provide an apparatus which may be run in the bore at the lower end of adrilling string or tubing to any desired point in the bore, which device may then be actuated to engage the wall of the bore and extract a sample of the formation at that point so that it may be recovered when the device is elevated to the mouth of the bore to enable the driller to determine accurately the character of the formation at that point in the bore.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawing, in which:

Fig. 1 is a view in central vertical section through the device showing the core extracting members in retracted position.

Fig. 2 is a similar view showing the core extracting members in projected position.

Fig. 3 is a transverse section taken on line 1IIIII of Fig. 2.

Referring more particularly to the accompanying drawing, I have there disclosed an apparatus II] which may be termed a side wall core extractor or a side wall formation sampler. This apparatus includes a cylindrical body member II carrying core extracting or sample taking members I2 and I4. The body II may be connected to the lower end of a string of drill pipe or tubing and run in the hole until the core extracting members I2 and I4 are aligned with the stratum of which it is desired to take a core or sample. During the running in operation, the core extracting members I2 and I4 are retained in a retracted position within the body II, which body is somewhat smaller in diameter than the diameter of the bore. When the body H has been properly positioned relative to the stratum of which a core or sample is desired to be taken, the core extracting members I2 and I4 are operated hydraulically to engage and penetrate the side wall of the bore and extract cores or samples therefrom. After the cores or samples have been taken, the coring or sampling members I2 and I4 may be retracted within the body II and which tends to constantly urge the piston I6 to its uppermost position. The body II is formed with a transverse socket or opening i9 below the cylinder I5 in which the core extracting members I2 and I4 are mounted for pivotal movement in a vertical plane. The core extracting members I2 and Id are here shown as substantially flat and are pivoted on a pintle 20 which extends transversely of the body I I at right angles to the transverse opening I9 and supported at its'ends in the body I I at the opposite sides of the transverse socket I9.

The lower end of the piston rod I1 is fitted with two downwardly depending arms 2| which are pivotally connected to the lower end of the piston rod II by a pivot pin 22. The lowermost end of one of these arms 2| is connected to the coring member l2 at a point eccentric to the pintle 2|], the other arm 2| being connected to the coring member I 4 at a point eccentric to the pintle 20. The connection between the piston rod l1 and the members I2 and I4 by means of the arms 2| is such, that when the piston I6 is moved downwardly against the action of the spring I8, the members I2 and I4 will be caused to swing outwardly and upwardly to engage and penetrate the side wall of the bore, and when the piston moves to its uppermost position in the cylinder I5, the members l2 and I4 will be caused to swing downwardly and inwardly within the transverse socket or opening I9.

It will be noticed that the outer or free end of each of the members IZ'and I4 is provided'with two projecting core tubes or sample takers 23 which are substantially tubular in form and threaded into the end thereof. The outer ends of these tubular core tubes or formation takers are open and the interior bore thereof is tapered with the larger diameter innermost, so that after a sample has been taken and the device brought to the mouth of the well, the core tubes 23 may be removed from the members I2 and I4 and the cores extracted from the tubes 23 by pushing them through the inner ends of the core tubes. This taper of the interior bore of the core tubes 23 causes retention of the cores in the tubes during the elevation of the tool to the mouth of the well.

- It will be noticed that each of the coring members I2 and I4 is provided with a protrusion 24 which likewise. penetrates into the side wall of the hole. This not only prevents the device from rotating when a core is being taken, but protects the core tubes from excessive weight being imposed thereon. 1

In operation of the device, the pin box 25 at the upper end ofthe body II is connected to the lower end of the drill pipe or other. tubing and by means thereof lowered into the bore. I may prefer to provide a pilot bit 28 at the lower end of the body II in the event that it is necessary to penetrate through a bridge in the hole.

During the period of lowering, the core extracting members I 2 and I 4 are folded into a protected position within the body II, as illustrated in Fig. 1, due to the fact that there is no hydraulic pressure above the piston I6 so that the spring l8 will tend to maintain the members I2 and I4 in the position illustrated. The body II is then lowered into the hole until ,the core extracting members l2 and I4 register with the stratum from which it is desired to extract a core or sample.

Hydraulic pressure is then created in the tubing above the piston I6 to force the piston downwardly to an extent causing the core tubes 23 and the protrusions 24 to engage the side wall of the hole. The minute such engagement is eflfected, weight is imposed on the body I I, which weight together with the hydraulic pressure will force the core extracting members I2 and II to a wide open position, as illustrated in Fig. 2, during which operation the core tubes 23 will penetrate into the formation and extract a core or sample therefrom.

It will be noticed that the protrusions 24 of the member's I2 and I4 will also penetrate into the formation so as to prevent excessive weight from being imposed on the tubes 23.

When the core has been taken, the body II is elevated and the hydraulicpressure above the piston I6 is relieved. This elevation of the body combined with the efiorts of the spring I8 will cause the core extracting members I2 and I4 to retract to the position within the body as illustrated in Fig. 1. The body is then removed from the hole and the core tubes 23 are unscrewed from the members I2 and I4. The cores may then be extracted from the core tubes 23 and inspected to determine the character of the formation-from which the cores or. samples were taken.

From the foregoing it is obvious that I have provided a comparatively simple tool which will be positive. in operation and by means. of which cores or samples may be very quickly and economically taken from the side wall' of a bore at any point therealong.

One of the principal uses of the present tool is that if the presence of a sand is known along the bore of the well, it not being known whether it is an oil bearing'or water bearing sand, this may be readily determined by running in my present apparatus and taking a sample thereof.

invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: 1. An apparatus of the character described comprising a body adapted to be positioned in a well bore at the lower end of a string of tubing,

core extracting means carried by the body and normally disposed within the confines thereof but capable of being projected laterally from the body into engagement with the walls of the bore, a piston in the body and connected to said core extracting. means and capable of operation to extend the sameby the creation of hydraulic pressure in said tubing.

2. An apparatus of the character described comprising a body adapted to be positioned in a well bore at the lower end of a string of tubing, core' extracting members pivotally mounted in the body and normally disposed within the confines thereof but capable of being projected laterally from the body into engagement with the wall of the bore to penetrate, the same, the penetrating portion of said members having core receiving sockets, and a hydraulically actuated member connected with said core extracting members and capable of operation to project the same upon the creation of hydraulic pressure in said tubing.

3. An apparatus of the character described comprising a body adapted to be lowered into a well bore at the lower end of tubing, said body having a transverse socket formed therein, a pair of core extracting members disposed in said socket and normally positioned within the confines thereof but capable of being projected laterally of the body to engage and penetrate the formation at. the sides of the bore, said members having'core receiving means to receive and retain a core when said members are so projected, a hydraulic piston arranged in said body and connected with said members whereby said members may be projected by the creation of hydraulic pressure in said'tubing above said piston.

4. An apparatus of the character described comprising a body adapted to be lowered into a 'well bore at the lower end of tubing, said body having a transverse socket formed therein, a pair of core extracting members disposed in said socket and normally positioned within the confines thereof but capable of being projected laterally of the body-to engage and penetrate the formation at the sides of the bore, said members having core receiving means to receive and-retain a core when said members are so projected, a hydraulic piston arranged in said body and connected with said members whereby said members may be projected by the creation of hydraulic pressure in said tubing above said piston, and spring means constantly tending to maintain said core extracting members in normal position.

5. An apparatus of the character described comprising a body adaptedto be lowered into a .well bore at the lower end of tubing, said bodv having a transverse socket formed therein, a pair of core extracting membersdisposed in said socket and normally positioned withinthe confines thereof but capable of being projected laterally of the body to engage and penetrate the formation at the sides of the bore, said members having core receiving means to receive and retain a core when said members are so projected, said body having a cylinder formed therein above said transverse socket, a piston in said cylinder con-. nected with said members whereby reciprocation of the piston will cause projection and retraction ofsaid members, said piston being actuated by hydraulic pressure created in said cylinder.

through said tubing.

6. A tool of the character described comprising a body adapted to be connected at its upper end i to the lower end of a string of tubing, a pilot bit at the lower end of said body;hydraulically actuated means positioned intermediate the ends ofthe body adapted to engage and extract cores from the side walls of a bore.

'7. A tool of the character described comprising a body adapted to be connected at its upper end with the lower end of a string of tubing and be lowered into a well bore by means thereof, by-

' draulically actuated core extractors normally positioned within the body but capable of being hydraulically actuated to project from the body laterally thereof and engage and penetrate the side walls of a bore to extract cores therefrom.

8. A tool of the character described comprising a body adapted to be connected at its upper end with the lower end of a string of tubing and be lowered into a well bore. by means thereof, hydraulically actuated core extractors normally positioned within the body but capable of being hydraulically actuated to project from the body laterally thereof and engage and penetrate the side walls of a boreto extract cores therefrom, and spring means constantly tending to 'maintain said core extractors within the body.

9. A tool of the character described comprising a. body adapted to be connected at its upper end with the lower end of a string of tubing and be lowered thereby into a well bore, said body having a transverse socket therein, a pair of oppositely swinging core extracting members mounted in said socket for vertical swinging movement whereby they may be positioned within said socket or projected laterally of the body into engagement with the side walls of the bore to penetrate the same and extract cores therefrom, hydraulically actuated means carried by the body for projecting said core extracting members from the body.

10. A tool of the character described comprising a body adapted to be connected at its upper end with the lower end of a string of tubing and be lowered thereby into a well bore, said body having a transverse socket therein, a pair of oppositely swinging core extracting members mounted in said socket for vertical swinging movement whereby they may be positioned within said socket or projected laterally of the body into engagement with the side walls of the bore to penetrate the same and extract cores therefrom, hydraulically actuated means carried by the body for projecting said core extracting members from the body, and springmeans normally maintaining said core extracting'members in normal position within said socket.

11. A tool of the character described comprising a body adapted to be connected at its upper end to a string of tubing whereby it may be positioned in a bore, said body having a transverse socket formed therein, a pair of oppositely swinging core extracting members pivotally mounted in said socket whereby they may be confined within said socket or projected laterally therefrom to penetrate the side walls of the bore, and means carried by the body and connected with said members for operating the same.

12. A tool of the character described comprising a body adapted to be connected at its upper end to a string of tubing whereby it may be positioned in a bore, said body having a transverse socket formed therein, a pair of oppositely swinging core extracting members pivotally mounted in said socket whereby they may be confined within said socket or projected laterally therefrom to penetratejihe side walls of the bore, and means carried by the body and connected with said members for operating the same, said means being hydraulically actuated to project said members laterally from the socket and spring actuated to return said members to a position within said socket. r

13. A tool of the character described comprising a body adapted to be lowered into a well bore,

said body having a transverse socket formed therein, a pair of members pivotally mounted in said socket to swing in a vertical plane whereby they may be projected from opposite sides of the body into engagement with the wall of a bore, said members having core extracting means positioned to penetrate the wall of the bore to extract cores therefrom when said members are projected laterally from the body and means for operating said members to project them into engagement with the sides of the bore and to retract them to a position within the socket, said means being hydraulically actuated to project said members laterally from the body and spring actuated to return said members to a position within the socket.

CLARENCE E. BURT. 

